在1xEV-DO系統中針對傳輸控制協定之跨層排程器設計

Abstract

本論文旨在提出一個針對增進傳輸控制協定(TCP)層效能的排程器設計概念，叫做基於傳輸控制協定之跨層排程器。其新排程器不只考慮所在之媒體接取控制層(MAC)的效能，也考慮傳輸控制協定層的效能。這個新提出的排程器主要概念是在不改變現有傳輸控制協定下，控制一個傳輸控制協定層封包在某些部份延遲的總合，包含在基地台的佇列等待延遲和無線段傳輸延遲，使的排程延遲造成的不必要之傳輸時間逾時（timeout）能減少。基於1xEV-DO模擬平台，模擬結果驗證了所提出的排程器可以增進傳輸控制協定層效能。

A new MAC scheduling algorithm called TCP Based Cross Layer Scheduler (TCLS) is proposed to improve TCP layer performance. The algorithm considers not only MAC layer performance, but also TCP layer performance. Without changing existing TCP protocol, the main concept behind TCLS is to control the sum delay of each TCP packet’s wireless transmission delay and queuing delay in base station, and prevent unnecessary TCP timeouts caused by scheduling delay. Based on 1xEV-DO simulation platform, simulation result verifies the improvement of TCP layer performance.